BELL Old Rotary Phone

[oskar270]

I have this old Bell rotary phone from the early 80's and I would like to install it in my workshop; it works when I plug it to wall jack except for the ringer which does not work. I had post this subject to another forum with no success so far and here are all the photos I have gathered.

http://s285.photobucket.com/albums/ll59/kolias/BELL%20Phone/  ( dead link 11/10/17 )

As you can see from the photos, there is a black wire which is not connected and I don't know if this is the reason.

The terminal blocks above the left bell are marked from left to right L1, L2, G, X, Y. Nothing is connected on the X & Y terminals. I have noticed this number on the network module QNB425EI. Also other markings I found on the phone are: NE 500, 78 L/N, Made in Canada, G – Type and on the ringer I found NE – C4A

Between the slate & slate/red wires from the ringer I had soldered a 0.47mfd/400V ceramic capacitor which had these markings: 9737MMK 63, 470 nK. I have removed now this capacitor because didn't do any good and that's why you will see on the photos these wires patched because they became too sort to reach the network.

I have also tested the ringer with an ohms meter and it looks ok. I got between the black and slate 970 (meter set at 2000) and between the red and slate/red I got 2.62 (meter set at 20).

I also want to mention that I know nothing about electronics / electrical

Any ideas?

[HarrySmith]

Hi and welcome to the forum. Here is a 500 wiring diagram that should help you out http://www.classicrotaryphones.com/forum/index.php?topic=2767.0
It is for a WE 500 but it should work for you. There are a couple of other variations in that thread you can also try.

[oskar270]

Thank you, I will give it a try tomorrow

[oskar270]

I try the new wiring from the link you sent based on the C4A ringer and it didn't work. (The other variations on that link are not applicable for my phone).

First the ringer does not work and in addition, now when I talk my voice sounds kind like echo and the other party says they hear my voice like far away.

Any other ideas?

[oskar270]

I was reading under "Technical Stuff" the post "Proper line-in wiring for your telephone" by TIPandRING dated Dec-27-2008 and I found it very interesting regarding my problem. However after I connected the Green and Yellow wires to L1 in my network, again the ringer does not work and my voice sounds funny when I talk on the mike.

Then I noticed further down on the same post there is discussion to connect also the Black wire from the ringer to L1. This I will do soon and test again to see the results.

Other ideas?

[oskar270]

Better wait for help because I noticed on "TipandRing" post mentioned above that there are 3 wires coming into the house; Red, Yellow and Green (his photo attached below for reference)

I only have 2 wires; Red and Green.

Is it safe to connect the Yellow wire to my center terminal?

[Bill]

I think it is fair to say that if your phone is a 500 set, it is "modern", not really "old". And in modern wiring, yellow (if present) is ground, and should be tied off (not connected to anything). Red and green, also called Tip and Ring, are the active wires. With very few exceptions, they can be connected either way to L1 and L2 in your phone. In your photo above, reference letter "A" shows the two conductor acetate (?) wire coming into the house - these are tip and ring.

In a modern set, yellow can only cause problems. Yellow was used in some older phones to accomplish some party-line functions, and in payphones to accomplish some signalling functions. But assuming you are not doing that, yellow should be tied off. If your phone still doesn't work, look for other misconnections in the phone, not in the red/green/yellow input wires.

Bill

[oskar270]

Thank you Bill for the education, now I understand the purpose of the Yellow wire.

Just to clarify, the photo you mentioned with reference letter "A" is not my installation. This photo is here for reference and only the bottom photo indicates my installation.

I'm waiting for someone to help me with any misconnections in the phone to solve my problem

[Bill]

Oskar -

I'd be glad to help, but it is really hard to go anywhere from photos. This is partly because some of the wires are obscured, no matter how careful you are, and also because a lot of the terminal labels can't be read. In addition, I'm not recognizing many of the phone internals from the photos. I imagine others are having trouble as well. Some hands-on time would help a lot. Where are you located?

Bill

[oskar270]

I'm in Montreal, Canada

On the link in my 1st post among the other photos there is a wiring diagram I made. Is this of any help?

I can also take any other photos you want

I can also try to troubleshoot my problem if I only new a bit more about how phones work. Do the red and green wires coming to the house do they also transmit the ringer voltage?

[oskar270]

Connecting the Line - in Red wire to the ringer Red and Line - in Green to the ringer Black, ringer does not work when someone calls.

But as I mentioned in my 1st post, ringer looks ok when I test it with my meter.

Can someone tell me if the ringer should work if I only have Red & Green incoming lines?

[LarryInMichigan]

oskar270,

The way that a ringer is connected is quite simple.  One side of the ringer coil is connected to one side of the phone line (L1 or L2/red or green), and the other side is connected to a capacitor which is connected to the other side of the phone line.  The WE type ringers like yours also add a resistor in series.  The capacitor is there to block DC current from flowing through the ringer coils, otherwise your phone line would be 'off hook' all the time.

The red wire  from your ringer should be connected to the terminal marked 'L2', the black wire should be connected to 'L1', the slate wire to 'K', and the slate-red to 'A'.  Forget about the yellow and black wires from the line cord.  If it still doesn't work, you can verify that there is conductivity through the ringer between the red and slate-red wires and between the black and slate.  The resistance between black and slate is supposed to be about 1KΩ.  If everything looks good, but the ringer still does not work, you can feel the clapper arm while the ringer should be ringing and determine if there is any vibration.  You may need to adjust the tension spring wire to allow the arm to move more easily.  You can also measure the AC voltage between the 'L2' and 'K' terminals.  There should be about 90V while ringing.  If there is no vibration or voltage, your ringer capacitor may be bad.  You can buy one at Radio Shack (1 μF/250 V - not electrolytic) and connect it between the 'A' and 'K' terminals.  If your ringer is bad, someone here can probably provide a replacement.

Larry

[Bill]

Oskar -

Yes, actually it does help. I'm looking at the diagram labelled "Revised" - wish I had seen it earlier.

First question - the terminals on the dial should each have a label. Can you read them and add them to your diagram?

Second question - you have three wires on the right going off to "phone". Since all of it is "phone", do these three wires go to the handset?

As Larry in Mich mentioned, the ringer may be connected wrong in some way - but not necessarily. There are a couple possibilities, but one question is, the phone should have a capacitor/condenser in it somewhere. Where is it? I'm having trouble identifying the capacitor in the photos. It may be internal to one of the blocks, and so not visible. Or I suppose it could be the orange disc, though that disc looks awfully small to me. What are the markings on the orange disc? Where is the orange disc connected to the other parts of the phone?
Is it (perhaps) connected between A and K? If so, and if it is the capacitor, it would make the ringer wiring OK, and it should be added to your diagram.

Larry asked if there is any vibration in the ringer when it should be ringing? This ringer has a ringer cutoff tab, which (I think) can be bent to stop the clapper from moving. See fig 2 and fig 3 in
http://wedophones.com/TheBellSystem/pdf/bsp/c-typeringer/501-250-303-7809.pdf

What is the gray disc beside the orange disc, and where is it connected? Perhaps a varistor? Markings?

Bill

[oskar270]

Decided to remove all wiring to be able to take good photos (although I marked each wire, I hope I can put them all back in order LOL).

The 1st photo shows all terminals ID

Second photo shows these blue and orange round things; the blue is marked RV2 and the orange RV1

Also I noticed the network has this ID: QMMI9A

Larry and Bill I printed your emails and I'm working to answer all your questions, probably I will make a new schematic

Thanks

[Bill]

Good photos - yes they help. As I understand the problem, the phone works perfectly except that the ringer doesn't ring. So that is what we are working on. There are only two components involved - the ringer and the capacitor - so we should be able to isolate the issue. I'm still having trouble finding the capacitor in the photos, so let's try something else.

First, you said that you tried connecting a 0.47 uF capacitor from A to K, and it didn't help. I was surprised - that seemed like a good move. You gave the capacitor markings as 9737MMK 63 470nK. Now the sad fact is that capacitor markings are harder to interpret than ancient Sanskrit. There is no standard, as there is for resistors - every manufacturer, and every type of capacitor, and every decade of manufacture, has a different system. So let's start by asking why you think this is a 0.47 uF capacitor? The 9737 sounds like a date code - 37th week of 1997 - so it isn't relevant here. The MMK suggests that this capacitor was made by Kemet, and the Kemet codes suggest (they are not definitive!) that 470 may be 47 pF, which is way WAY too small.

In your picture 14, I'm not sure what the significance of the component photos is, but the component labelled 0.1 uF capacitor is almost certainly NOT an 0.1 uF capacitor.

Assuming that this is not the answer, let's try some temporary rewiring. We will put the wires back, so remember what you did!
1. The ringer red wire is connected to L2. Leave it there, along with the other wires.
2. The ringer black wire is connected to F. Remove it from F. Get a 1 uF capacitor. Connect one capacitor wire to the ringer black wire - the one you just removed from F - and to nothing else. Connect the other capacitor wire to L1, leaving the other wires on L1 in place.
3. The slate and slate-red ringer wires are connected to A and K. Remove them from A and K, and connect them together, and to nothing else.

Call the phone, and see if it rings. If it does not ring, does it vibrate as described by Larry?

Report the results. We'll get there.

Bill